Process for the flame-proofing of fibrous materials consisting of polyester fibers and cellulose fibers

ABSTRACT

FIBROUS MATERIALS ESSENTIALLY CONSISTING OF MIXTURE OF POLYESTERS AND CELLULOSE ARE RENDERED FIRE-PROOF BY TREATMENT WITH THE AMMONIUM SALT OF BIS-(HYDROXYMETHYL)PHOSPHINIC ACID. THIS TREATMENT IMPROVES, FURTHERMORE, THE SOFT HANDLE OF THE GOODS.

United States Patent 3,600,219 PROCESS FOR THE FLAME-PROOFING OF FIBROUSMATERIALS CONSISTING 0F POLYESTER FIBERS AND CELLULOSE FIBERS MartinRenter, Kronberg, Claus Beermann, Neu-Isenburg, and Fritz Linke,Kelkheim, Taunus, Germany, assignors to Farbwerke HoechstAktiengesellschaft vormals Meister Lucius & Bruning, Frankfurt am Main,Germany No Drawing. Filed Sept. 26, 1968, Ser. No. 763,013 Claimspriority, application Germany, Sept. 30, 1967, P 16 19 055.9 Int. Cl.(109k 3/28; D06m 13/44 US. Cl. 117-136 2 Claims ABSTRACT OF THEDISCLOSURE Fibrous materials essentially consisting of mixtures ofpolyesters and cellulose are rendered fire-proof by treatment with theammonium salt of bis-(hydroxymethyl)- phosphinic acid. This treatmentimproves, furthermore, the soft handle of the goods.

It is known (SVF-Fachorgan 1964, 798) that the flameproofing agentswhich are effective for cellulose fibers do not flame-proof polyesterfibers, for example those of polyethylene glycol terephthalate. Thisalso applies to mixed fabrics made of both types of fibers.

Belgian Pat. 604,507 describes flame-proofing impregnations of polyesterfabrics with solutions of the ammonium salts of polyvinylphosphonicacid. These impregnations, however, deteriorate the handle and render ithard.

Now, we have found that fibrous materials which consist essentially ofmixtures of polyester fibers and cellulose fibers can be renderedflame-proof when they are treated with solutions of the ammonium salt ofbis-hydroxymethyl-phosphinic acid.

It is surprising that this treatment does not impair the handle of thematerials, but that it rather improves it and renders it softer thanbefore. Instead of the ammonium salt of purebis-hydroxymethyl-phosphinic acid, there may also be used the ammoniumsalts of industrial mixtures with its anhydration products and withmono-hydroxymethyl-phosphinic acid.

As cellulose fibers, there may be used those of natural cellulose, forexample cotton, or of regenerated cellulose, for example viscose. Theirmixtures with polyester fibers in mixing proportions of about 20:80 upto about 80:20, especially those with a higher polyester portion, may besubjected to the treatment of the invention in unwoven form or in theform of fabrics or knit goods, and in dyed or undyed state. The usualpresence of small proportions of other known types of fibers does notaffect the finishing effect.

The process of the invention is carried out by impregnating in knownmanner, for example on the foulard, the fibrous material at roomtemperature with about a to about 40% solution, especially in water, ofthe ammonium salts of the present invention. The impregnated fabric issqueezed to an increase in weight of about 40 to about 100%. The fibrousmaterials are then dried in the usual manner at a temperature in therange of from about 40 3,600,219 Patented Aug. 17, 1971 ice to about 180C., depending on the relative proportions of the fibres and on thedyeing.

The impregnation solutions of the present invention may, if desired,also contain other usual textile auxiliary agents, for examplehydrophobing agents, oleophobing agents, pigments, and so on.Advantageously the impregnation solution can be utilized in combinationwith anticreasing agents, in particular with the knowncycloethylene-urea derivatives.

The following examples illustrate the invention but they are notintended to limit it thereto:

EXAMPLE 1 A twill-like fabric g./m. consisting of 70% of polyethyleneglycol terephthalate and 30% of cotton was impregnated on the foulard atroom temperature with an aqueous solution of g./l. ofbis-hydroxymethyl-phosphinic acid, which was neutralized withconcentrated ammonia solution. The impregnated fabric was squeezed toeffect a weight increase of about 65%. The fabric was then dried atabout 100 C. The fabric, thus treated, had an agreeably soft handle anda very good flame-protecting finish, as shown by a length of burn ofabout 7 cm. in the test according to DIN 53,906 (German IndustrialStandards) and a burn angle of about 25 in the arc test apparatus(Melliand Textilberichete 1967, pages 215- 217).

EXAMPLE 2 A poplin fabric g./m. consisting of 50% of polyethylene glycolterephthalate and 50% of cotton (Warp: twisted) yarn (weftzsingle yarn)and dyed with Indanthren Blue RK (Colour Index No. 70,000), wasimpregnated with an aqueous solution of 180 g./l. of the ammonium saltof bis-hydroxymethylphosphinic acid as described in Example 1, squeezedand dried. The fabric thus treated had a soft handle and a goodflame-proofing finish (length of burn 7.5 cm., angle of burn about 27).

Similar good results were obtained by impregnating a flannel g./m.consisting of 80% of polyethylene glycol terephthalate and 20% ofviscose staple fiber and printed with Indanthrene Blue RK, and a satintype furnishing fabric (220 g./m. consisting of 67% of polyethyleneglycol terephthalate and 33% of cotton.

EXAMPLE 3 A warp-knitted fabric (200 g./m. consisting of 50% ofpolyethylene glycol terephthalate and 50% of cotton was impregnated atroom temperature on a winch beck with an aqueous solution of 180 g./l.of the ammonium salt of bis-hydroxymethyl-phosphinic acid. The fabricwas then centrifuged until the increase in weight was about 80% anddried at about 80 C. The knitted fabric had a soft handle and, with alength of burn of 8 cm. and a burn angle of about 25, it represented agood flameproofing finish.

We claim:

1. A process for the flame-proofing of fibrous materials consisting of20 to 80% by Weight of cellulose fibers and 80 to 20% by weight ofpolyester fibers, which comprises impregnating said materials with anaqueous solution containing about 10 to about 40% by weight of theammonium salt of bis-(hydroxymethyl)-phosphinic acid, squeezing saidmaterial to an increase of weight of about 40 to about 100% and dryingsaid material.

2. The process as claimed in claim 1, wherein impregnating is carriedout at room temperature and drying is effected at a temperature in therange of from 40 to References Cited UNITED STATES PATENTS Pollak et a1.117137 Rauhut et a1. 117136X Polansky et a1. 117-138.8UX Toy et al.260502.4 Chance 117-136X Chance 8-120X 4 Coates et a1. 117-143X White eta1. 11713 8.8X Ingram 117-139.5X Klein et a1. 260502.4X

Singleton 117138.8X Chance et a1 117136X WILLIAM D. MARTIN, PrimaryExaminer H. J. GWINNELL, Assistant Examiner US. Cl. X.R.

117-] 38.81 139.5CQ, 143R

